Method for making a road base material using treated oil and gas waste material

ABSTRACT

The present invention provides a novel method to produce grade road base material using recycled oilfield waste, called “oil and gas waste,” more specifically, drilling waste and aggregate and a novel road base material. Hydration and mixing of the waste materials along with a binder, will achieve an irreversible pozzolanic chemical reaction necessary for stabilization into a road base. An asphalt emulsifier may be included in the binder to manufacture asphalt stabilized road base. The entire method is a cold batch process.

This application is a continuation of U.S. patent application Ser. No.10/801,410, filed Mar. 16, 2004, which is a continuation-in-part andclaims priority from U.S. patent application Ser. No. 10/062,119, filedJan. 31, 2002, which in turn claims priority from and the benefit ofU.S. Patent Application Ser. No. 60/299,225, filed Jun. 19, 2001. The'410 application, from which this application is a continuation thereof,also claims priority from and is a continuation-in-part of U.S.application Ser. No. 10/736,337, filed Jan. 15, 2003, which applicationin turn claims priority from U.S. Application Ser. No. 60/433,425, filedJan. 13, 2002.

FIELD OF THE INVENTION

Applicant's invention relates to a method for making road base usingprimarily waste material from oil and gas waste solids and non-hazardousindustrial waste or natural occurring porous or semi-porous material tocreate a asphalt stabilized road base that is environmentally safe andmeets industry standards for quality materials. More particularly, itrelates to combining, in a cold batch mixing process, treated oil andgas waste material with aggregate to provide the major components forthe roadbed base material.

BACKGROUND OF THE INVENTION

Because of their importance in all aspects of both business and privatelife, the construction of roads has historically been of primeimportance to a society. That importance remains today. However, it hasalso become more apparent in recent years that most resources are notinfinite but rather, are depletable. Additionally, disposing of wastematerials is becoming harder and harder due both to space limitationsand liability resulting from waste materials entering the environment.

Thus, there is a need for developing methods to recycle waste productsinto new, usable products. If the components of roadbeds can be obtainedfrom the waste products of other products and processes, then both wasteproduct production is decreased and new product consumption isdecreased. Further, it is advantageous to recycle waste products due tothe economic advantage of using recycling materials and thus compoundingreturn on the original costs of the products.

SUMMARY OF THE INVENTION

The primary focus of the invention is the treatment of oil and gas wastefor use with other materials to make a suitable road base material.Treatment of oil and gas waste is done to remove at least a portion of aliquid component, typically primarily oil and water to yield a treatedoil and gas waste portion which is then combined with an aggregate and abinder and stabilizer to produce a suitable road base material. Thetreatment of the oil and gas waste, while yielding a liquid portion mayalso yield other recyclable or useable products such as clean mud. Cleanmud is a product often desired by oil and gas well drillers. Thus, it isthe desired result of the present invention of using oil and gas wastematerial treated such that it is converted into a material that isuseable and, excepting perhaps “waste water” which may be reinjected,yields environmentally friendly, economically valuable components.

Turning to the separation of the liquid component from the oil and gaswaste material it is anticipated by the present invention that there area number of methods of liquid portion removal. One such method is anovel means of stacking of oil and gas waste, to yield gravity inducedseparation of some of the liquid portion from the solid portion. Anothermethod is mechanical separation, such as by a centrifuge. A third methodis mixing with a dry material, such, for example, as soil, overburden,or caliche limestone.

The present invention provides a novel method to produce road basematerial using waste products from one or both of two industries: oiland gas well drilling and from construction and/or demolition andmanufacturing projects. The present invention also provides for a novelroad base composition. The oilfield waste is typically comprised ofhazardous and/or non-hazardous oilfield solid or liquid waste such aswater based drilling fluid, drill cuttings, and waste material fromproduced water collecting pits, produced formation sand, oil baseddrilling mud and associated drill cuttings, soil impacted by crude oil,dehydrated drilling mud, waste oil, spill sites and other like wastematerials tank bottoms, pipeline sediment and spillsite waste. Oilfieldwaste may include waste or recycled motor oil, petroleum based hazardousor non-hazardous materials, such oilfield waste materials arecollectively referred to as “oil and gas waste material.” They typicallyhave a solid component and a liquid component, the liquid componentincluding quantities of oil and water. The solid components may be, inpart, particulate.

An aggregate component of the road based material may include anon-hazardous industrial waste as defined in more detail below or anynatural occurring stone aggregate such as limestone, rip rap, caliche,sand, overburden, or any other naturally occurring porous material.There may or may not be preparation of the aggregate material prior tocombining with the treated oil and gas material to form the primarycomponent of the road based material of Applicant's present invention.

The construction and/or demolition or manufacturing waste component ofthe aggregate material is typically comprised of non-hazardousindustrial waste such as waste concrete, waste cement, waste brickmaterial, gravel, sand, and other like materials obtained as waste fromindustrial construction, demolition sites, and/or manufacturing sites.Such materials are collectively referred to as “non-hazardous industrialwaste.”

One application of the method of the present invention provides forrecycling the oil and gas waste material and the non-hazardousindustrial waste to combine to produce road base. Another application ofthe present invention provides for recycling the oil and gas wastematerial and an aggregate including limestone, rip rap, caliche, or anynaturally occurring porous or semi-porous material to combine to produceroad base. Hydration and mixing of the treated oil and gas wastematerial and aggregate along with a binder such as cement, fly ash,lime, kiln dust or the like, will achieve an irreversible pozzolanicchemical reaction necessary for a road base. An asphalt emulsifier maybe included in the binder to manufacture asphalt stabilized road base.The ingredients are typically mixed in a cold batch process.

Solid waste from the oil and gas waste material typically containsnaturally occurring aluminas and silicas found in soils and clays. Theadded pozzolan will typically contain either silica or calcium ionsnecessary to create calcium-silica-hydrates andcalcium-aluminatehydrates. A pozzolan is defined as a finally dividedsiliceous or aluminous material which, in the presence of water andcalcium hydroxide will form a cemented product. The cemented productsare calcium-silicate-hydrates and calcium-aluminate-hydrates. These areessentially the same hydrates that form during the hydration of PortlandCement. Clay is a pozzolan as it is a source of silica and alumina forthe pozzolanic reaction. The aggregate including natural stone aggregateor non-hazardous industrial waste adds structure strength and bulk tothe final mix.

The process of creating a stabilized road base using an aggregateincluding non-hazardous industrial waste and oil and gas waste materialmay incorporate a water based chemical agent such as waste cement,varying amounts of aggregate and waste to produce a cold mix, stabilizedroad base product. An aggregate crusher may process the inert material(typically aggregate including the non-hazardous industrial waste ornatural stone aggregate), into the size and texture required (from, forexample ½″ to 4″). The aggregate is added to the treated oil and gaswaste material at a desired ratio. It has been found that an approximateratio of one-to-one treated oil and gas waste material to aggregateprovides a good mix. This could vary depending upon the degree ofcontamination or the quality of the oil and gas waste. A chemicalreagent is added to congeal the mixture. An asphalt emulsifier is addedto create an asphalt stabilized road base. The resulting product is astabilized road base that not only is of a superior grade, but will notleach hydrocarbons, chlorides or RCRA metals in excess of constituentstandards set forth in the Clean Water Act.

In order to further the environmental objectives of the presentinvention, it is desirable to isolate the oil and gas waste materialfrom the environment prior to mixing. Thus, while the aggregate may bestored on the ground, oil and gas waste material should be storedsurrounded by a berm and/or placed on a cement pad, or otherwiseisolated by a physical barrier that will prevent leaching of liquidcontaminates into the soil. This also prevents storm water runoff. Themanufactured road base typically is mixed, processed, and likewisestored surrounded by an earthen berm and on a cement pad and/or otherphysical barrier that will prevent leaching of liquid contaminates intothe soil. Thus, the present invention provides a novel method that willproduce grade road base material.

Among the objectives of the present invention are to:

a. combine treated oil and gas waste material with aggregate to producea stabilized road bed composition;

b. reduce waste from oil drilling, and construction/demolition andmanufacturing;

c. reduce the use of new materials for roadbeds;

d. provide a method for producing roadbed material at a lower cost thanconventional methods;

e. provide methods of treating oil and gas waste material to yield amaterial that can be used for preparing a stabilized roadbed and alsoyield clean mud and water;

f. combine treated oil and gas waste material with non-hazardousindustrial waste or naturally occurring material to yield anenvironmentally safe, usable, stabilized road bed composition;

g. provide simple methods of removing a liquid component from oil andgas waste material;

h. recycle aggregate waste from construction, demolition andmanufacturing sites; and

i. provide for a single site or location to which oil and gas waste istransported and at which it is treated and mixed to a road basecomposition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overview of a process of storage and treatment by drymixing the oil and gas waste material.

FIG. 1A is a generalized view of a process of Applicant's presentinvention.

FIG. 2 is a flow chart illustrating an overview of a process ofcombining treated oil and gas waste material and aggregate to produce,typically in a pug mill, waste mix 14, which cures to form a novel roadbase.

FIGS. 2A-2D illustrate Applicant's novel method and device for stackingoil and gas waste material.

FIGS. 3 and 3A represent preferred alternate embodiments of a process oftreating the oil and gas waste material to prepare it for combinationwith the aggregate waste material.

FIG. 4 shows an alternate preferred embodiment of Applicant's presentinvention that may be incorporated in whole or in part into previousembodiments of Applicant's present invention.

FIG. 5 illustrates an alternate preferred embodiment of Applicant'spresent invention that may be incorporated in whole or in part into theembodiments set forth here and above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1A illustrates an overview of the steps of Applicant's presentinvention, Applicant provides for, in obtaining step 1A, obtaining oiland gas waste from an oil and gas waste site as set forth in more detailbelow and transferring the waste to a treatment and mixing site. Thesecond step, the obtaining step 1B, is that of obtaining an aggregate,typically inert, from a natural source such as limestone rock, caliche,rip rap, sand, dirt or the like or, as waste material from aconstruction, manufacturing, or demolition site. Step 2 is the treatmentof oil and gas waste to remove fluids and obtain water and recyclablematerial, which may be further processed. The third step is some form ofmixing (as described in more detail below) wherein treated oil and gaswaste is combined with aggregate and other material to provide anenvironmentally safe roadbed.

Turning back to the oil and gas waste, it is typically transported tothe treatment site where Applicant's novel treatment provides severalmethods of removing at least some of the fluids, from the oil and gaswaste material to provide a treated oil and gas waste material road basecomponent which then is mixed with the aggregate to form a road base. Asis apparent from FIG. 1A, the treatment step, step 2 removes water andalso provides for recyclable or reusable material, such as clean mud andoil in step 2A. Further, it is seen that step 3, a step of mixing, mayinclude not only the mixing of the aggregate with the treated oil andgas waste, but also mixing in other material such as binder, emulsion,etc., as set forth in more detail below. The result of the novel processis to provide a novel road base composition which is made up of treatedoil and gas waste material and an aggregate and to apply suchcomposition to a road base location.

Turning to FIG. 1, it is seen that, what is received from the oilfieldsite (32) at mixing site (16) is either tank liquids (30A) or trucksolids (30B) sometimes called “cuttings”. We will call these materialscollectively oil and gas waste material (10A). Upon arrival at mixingsite (16), tank liquids (30A) may be deposited into a leak proof liquidstorage tank (11). Truck solids (30B), which have a more solid likeconsistency than the tank liquids (30A), may be deposited on animpervious layer (19) and contained, typically, in a earthen storageberm (13). FIG. 1 shows that tank liquids (30A) and truck solids (30B),collectively referred to as oil and gas waste material (10A) is obtainedfrom an oilfield site (32) including but not limited to drilling sites,pit clean-up sites, spill clean-up sites, blow-out sites and oil and gasexploration, pipelines and refining industry or production sites.Typically the oil and gas waste material (10A) will be either “liquids”transported away from the oilfield site (32) in vacuum trucks or wasteof a more “solid” or “slurry” consistency and transported in dumptrucks. The oil and gas waste material (10A) is transported from theoilfield site (32) to a mixing site (16) by a first transport such as bya vacuum truck for liquids (“tank liquids”) (30A) or a second transportsuch as a dump truck for the “slurries” (“truck solids”) 30B. FIG. 1illustrates the dry mixing method of treatment; truck solids (30B) maybe combined with soil (15) or other dry, absorptive indigenous materialto help dry them and then stored on an impervious layer (19) as driedtruck solids (17) in a storage pile (19A) on an impervious layer (19).The impervious layers disclosed herein are man-made, as from concrete,plastic, steel, the road base material described herein or the like.Indeed, all of the storage and treatment of the oil and gas wastematerial (10A) may take place in an enlarged enclosure the bottom ofwhich has an impervious layer (19) and optionally, sides of whichinclude a storage beam (13) made of either concrete or some othersuitable material.

The next step in handling the oil and gas waste material (10A) is totreat it to at least remove some of the liquids therefrom (typically oiland water) so as to prepare a treated oil and gas waste/road basecomponent material (29) for mixing in the pug mill (18) to produce roadbase (20). Applicant provides a number of processes to treat the oil andgas waste material (10A). These processes include “dry mixing” asillustrated in FIG. 1, “stacking” as illustrated in FIG. 2B and“mechanical separation” as illustrated in FIGS. 3 and 3A. FIG. 1illustrates a treatment of oil and gas waste material 10A.

Turning to FIGS. 2A-2D, Applicant's treatment by stacking isillustrated. In this preferred embodiment of treatment of oil and gaswaste by way of a draining/evaporation process, the draining induced bygravity and the weight of the waste material itself is used along with aunique apparatus including a drainage assembly (60) to help remove oiland other liquids from either the truck solids (30B) or a mixture oftruck solids (30B) and tank liquids (30A). It is pointed out here thatit is preferable that the oil and gas waste material (10A) be treated toremove some of the liquids as it then makes the mixing of the road bedcomposition more effective. Typically, when the treated oil and gaswaste material (10A) is paint filter dry or thereabout, it issufficiently dry or damp to be processed in the pug mill. Moreover, itis not necessary for all the fluids to be removed from the oil and gaswaste material (10A) which may in fact, be somewhat damp aftertreatment.

Turning back to FIG. 2A it is seen that the stacking step (28A) includesa step of providing a drainage assembly (60) which includes a screenedenclosure (62) typically three-sided and contained within the animpervious enclosure (64). More specifically, drainage assembly (60) isdesigned to contain within impervious enclosure (64) the screenenclosure (62) which is usually constructed from rigid frame member(62A) consisting of angle iron welded or bolted together, which framemembers secure screened walls (62B), which screened walls may be madefrom a suitable screening material or expanded metal, with holes,typically in the range of sixty mesh to ¼ inch. The screened enclosure(62) is located in an impervious enclosure (64), which imperviousenclosure includes a bottom wall (64A) and a side wall portion (64B). Itis seen that the dimensions of the screen enclosure (62) are such thatthere is a gap created between screened wall (62B) and side wall (64B)of the impervious enclosure (64). It is in the gap (65) created by thedimensions of the screened enclosure (62) and impervious enclosure (64)respectively, that drainings (71), that is liquids comprising typicallyoil or some water, collect. Within screened enclosure (62) and typicallypiled such that its vertical height exceeds the length or width of thescreened enclosure (62) is stacked oil and gas waste (59) which iscomprised of either truck solids (30B) or a combination of truck solids(30B) and tank liquids (30A). Stacking the stacked oil and gas waste(59) in a manner so that is has a substantial vertical dimension(height) helps to ensure that there is sufficient weight to squeeze outdrainings (71), which may be then evacuated either continuously orperiodically from gap (65) through the use of a pumping or vacuum system(66). The pumping system includes pump (66A) and an engaging tube orhose (66B) or a vacuum hose attached to a vacuum truck (not shown). Tubeor hose (66B) has a first end for immersion in the drainings (71) and aremoved end outside impervious enclosure for transporting drainings to adesired site. Pump (66A) may be electric or hydraulic or any othersuitable means and may be float controlled for it to be activated whendraining (71) reaches sufficient depth within impervious enclosure (64).

An alternate preferred embodiment of Applicant's drainage assembly (60)there may be troughs or grooves (65) provided in the bottom wall (64A)of impervious enclosure (64) to assist in the draining of the stackedoil and gas waste (59) (See FIG. 2B).

The drainage assembly (60) may be any size, but is preferably designedto contain from 1 yard to 300,000 yards of stacked oil and gas waste(59) which may be dumped into the screened enclosure (62) using a frontend loader or by dump truck or vacuum truck. They may be left to allowfor the draining anywhere from a day to ten days or longer dependingupon how saturated they are at the beginning of the treatment process.They are then removed from the screened enclosure (62) by any suitablemethod and are then typically ready for transport to the pug mill formixing.

FIGS. 2C and 2D are views of an alternate preferred embodiment ofApplicant's drainage assembly (80). This embodiment differs from theembodiment illustrated in FIGS. 2A and 2B in several respects. First,the stacked oil and gas waste (59) is enclosed in a three-sided orwalled mesh enclosure (82). That is, drainage assembly (80) includes athree-walled mesh enclosure (82) that consists of a side wall (82A), aback wall (82B) and a second side wall (82C), opposite side wall (82A).The three-walled mesh enclosure has an open front (82D). The meshenclosure (82) lies within concrete retainer shell (86) or imperviouslayer and slightly spaced apart therefor to create a gap (65). Retainershell (86), typically made from concrete and about three feet high, hastypically three walls: side wall (86A), back wall (86B), second sidewall (86C), the second side wall being opposite the first side wall. Theretainer shell has an open front (86D) to allow dump trucks to back inand dump their load of oil and gas waste. A floor (86E), typicallyconcrete, is provided.

The retainer shell is typically about 100 feet by 100 feet with the backand two side walls about three feet high. Further, the floor istypically slanted a few degrees from horizontal dipping towards the backwall to allow liquids to drain to the back rather than out the openfront.

Mesh or screen sections (84) typically come in 4-foot by 8-foot sectionsand can be laid lengthwise inside the side and back walls of theimpervious enclosure spaced apart therefrom by the use of steel braces(88) set vertically on the floor and typically having a length of aboutfour feet (representing the height of the 4′×8′ sections) which lay onthe concrete floor. The braces will prevent the mesh or screen (84) fromcollapsing from the weight of the oil and gas waste material stackedagainst it and the braces provide for a gap (65), usually about sixinches or so, from which a pump or vacuum system and related plumbingmay be provided to remove liquids accumulating therein. It is seen thatacross the top of the beams enjoining a top perimeter of the wire ormesh section is a closed top (90) typically with an access door (90A).The function of the closed top is to prevent any oil and gas wastematerial stacked too high from falling over the top perimeter of themesh section into the gap between the mesh section and the concretewall. The access door may be opened to periodically insert a hose orpipe to evacuate accumulated liquids from gap (65). It is noted withreference to FIG. 2D that mesh typically stands a bit higher than thetop of the three walls of the retainer shell. The space between the topof the impervious layer and the closed top (90) may be left open orclosed with a suitable member. Closing that area would of course preventaccidental spillage of material into gap (65).

The material that accumulates in the gap is oil with some water and maybe sent to the mud tank or used to add to clean mud. It further may beseparated, having an oil component and a water component with the watercomponent disposed of, and the oil component used to add to the cleanmud.

As is illustrated in FIG. 2, the oil and gas waste treatment (28) mayalso treat the oil and gas waste (10A) to remove a clean mud component(23), and a water component (25), yielding treated oil and gaswaste/road base component material (29). Such treated oil and gaswaste/road base component material (29) may then be combined with stone(42), “sized” stone (44), non-hazardous industrial waste (12), or“sized” non-hazardous industrial waste (37) or a combination of thepreceding. These may be combined directly with the treated oil and gaswaste/road base component material (29) in a pug mill (18) or othersuitable mixer or may be combined to form a pre-mix (31), which is thendeposited into a pug mill (18) for further combining the two componentstogether and for adding such as portland cement (22) and a binder suchas asphalt emulsion (24) to yield, upon curing, the stabilized road base(20) (water may be added as necessary).

The second of the two primary components of the stabilized road base(20) is an aggregate component (61) which is collectively either stone(42) (naturally occurring) and/or non-hazardous industrial waste (12).This non-hazardous industrial waste (12) typically consists of inertaggregate material, like broken up brick or cinderblock, broken stone,concrete, cement, building blocks, road way, and the non-metallic andnon-organic waste from construction and demolitions site.

Non-hazardous waste (12) can be obtained from many sources and have manycompositions. It includes waste brick materials from manufacturers,waste cement or other aggregate solid debris of other aggregate fromconstruction sites, and used cement and, cement and brick from buildingor highway demolition sites.

Aggregate sites (34) include construction sites, building and highwaydemolition sites and brick and cement block manufacturing plantsquarries, sand, dirt, or overburden or caliche pits. The aggregate istransported by dump trucks or the like to mixing site (16) where it maybe separated down to a smaller size, that is, into aggregate particlestypically less than 1½″ in diameter by running them through a screen(33). Any material that is left on top of the screen may go to a crusher(35). That material may go back to the screen (33) until, fallingthrough the bottom of the screen and measuring less than about 1½″ insize. This will result in what is referred to as “sized” aggregate (30).This sized aggregate (30) is the aggregate component of the stabilizedroad base (20). It may then be combined with the treated oil and gaswaste/road base component material (29) in a pre-mix (31) as by usingbackhoes or loaders to scoop treated oil and gas waste/road basecomponent material (29) to physically mix with sized aggregate (30) (orunsized aggregate) to create a pile or batch of pre-mix (31), which thencan be added to the pug mill (18). Optionally, this premix (31), if ithas sufficient dampness from residual oil and moisture, may be combinedwith sufficient portland cement (22) to coat the particles, beforeputting it into the pug mill (18). As set forth above, treated oil andgas waste/road base component material (29) may be deposited directlyinto the pug mill (18) and sized aggregate (30) can be separately dumpedinto the pug mill (18) and the material mixed directly without a pre-mix(31). Note that portland cement (22) and asphalt emulsion (24) may alsobe added to the pug mill (18) while the two primary components, treatedoil and gas waste/road base component material (29) and aggregate arebeing mixed. Typically, the treated oil and gas waste/road basecomponent material (29) and aggregate (30) are mixed in a ratio of about50/50, but may be between 20/80 and 80/20. After the material isthoroughly mixed in the pug mill (18), it is deposited on the ground andmay be contained by a berm (13) on a impervious layer (19) for curing(typically for about 48 hours). At this point, leach testing (40) canalso be performed to determine whether or not the ratios of any of thematerials need to be adjusted. Leach testing is usually done at a lab toensure that materials from the road base do not leach into the ground.

The oil and gas waste material (10A) is comprised of hazardous andnon-hazardous hydrocarbon based discarded material by oil and gasexploration production, transportation, and refining industries. Oil andgas waste material may include water base drilling fluid, drillcuttings, waste material from produced water collecting pits, producedformation sand, oil based drilling mud and associated drill cuttings,soil impacted by crude oil, dehydrated drilling mud, oil, pipelines andrefining industries and like waste materials. It may be “dried” by oneor more of the novel drying processes disclosed herein. The term oil andgas waste material as used herein is not intended to be limited bydefinitions found in various codes or statutes.

Typically the oil and gas waste material (10A) contains enough liquidssuch that the aggregate (61) will likely become saturated if a mix isprepared without removal of some liquids, Therefore, the oil and gaswaste treatment (28) of the tank liquids (30A) or truck solids (30B) isusually required. Oil and gas waste treatment (28) may also be used whenclean mud is desired, since clean mud is often readily saleable. The oiland gas waste treatment (28) results in the production of clean oil andgas waste/road base component material (29) from the oil and gas wastematerial (10A).

The term “dry” is relative and means less liquid than before oil and gaswaste treatment (28), typically, resulting in the loss of sufficientliquid such that mixing with the aggregate (61) will not result insaturation of the combination. If an oil and gas waste treatment (28) isused, then the treated oil and gas waste/road base component material(29) are mixed with the aggregate (61) and portland cement (22) andemulsion (24) in a ratio that results in a stabilized product. Thatratio is determined by testing leachability of the roadbase for Benzeneand RCRA metals; also for strength by testing for compressive strengthand vheem stability, pH and chlorides. The ratio may be between 20/80and 80/20, typically about 50/50. Whether oil and gas waste material(10A) is mixed with aggregate (61) directly in a dry mix (17), or if oiland gas waste (10A) is subjected to oil and gas waste mechanical orstacking treatment and treated oil and gas waste/road base componentmaterial (29) are mixed with aggregate (61), an oil/aggregate mix (14)results from by the combination.

Typically, aggregate (61) is optimally sized to ¾ inch to 1½ inchdiameter pieces but may include a substantial portion smaller than ¾″.Therefore, a determination of desired size is made and, if the aggregatewaste is in pieces that are determined to be too large, they may becrushed in a crushing process (35) such as by a jaw crusher, to obtainthe desired size prior to being added to the treated oil and gaswaste/road base component material (29).

It has been found that a pug mill (18) provides adequate characteristicsfor proper mixing. The characteristics of a good mixer are consistency,coatability and durability. An emulsion (24) is added to theoil/aggregate waste mix (14) in the pug mill (18). The emulsion (24)serves to hold or bind the treated oil and gas waste/road base componentmaterial (29) to the aggregate waste (12) when the components are mixedand cured. The stabilizer (22) is, typically, comprised of portlandcement. A binder (24) is also provided, typically asphalt emulsion.While the portland cement and asphalt emulsion can be added in desiredquantities, it has been found that portland cement added in range of½-10% of the final product weight and asphalt emulsion added in range of½-10% of the final product weight provides good characteristics for thefinished product. The oil/aggregate waste mix (14), binder (24), andstabilizer (22) are mixed and cured and the final product, stabilizedroad base (20) as determined by compressive strength testing andleachate testing results. Portland cement and asphalt emulsion are addedto the waste mix (14) and mixed into the pug mill (18) or may be addedseparately to the pug mill (18). Optionally, treated oil and gaswaste/road base component material (29) which is sometimes damp, may becoated with portland cement before it goes into the pug mill (18). Thepug mill mixing (18) is a cold batch process.

More details of Applicant's oil and gas waste material treatment (28)are provided for in FIGS. 3 and 3A. It will first be noted that one ofthe purposes of treating oil and gas waste material (10A) may be toderive from it clean mud (23) which can be sold to oil and gasoperators. Secondly, water is taken out of the oil and gas wastematerials to be reinjected or otherwise disposed of. Finally, themajority of the oil and gas waste material (10A), upon treatment, willresult in treated oil and gas waste/road base component material (29),that is, oil and gas waste material (10A) from which at least someliquids have been removed.

Turning now to FIGS. 3 and 3A, it is seen that tank liquids (30A) andtank solids (30B) may be treated differently to achieve the removal of aliquid component and for the purposes of obtaining clean mud. Turning toFIG. 3A, it is seen that tank liquids (30A) are typically stored in tankliquid storage (11) from which they may be piped to and deposited on thetop of a fine shaker (41) which will typically remove off the topthereof a damp solids component (63). However, a substantial portion ofthe tank liquids (30A) will work through the fine shaker (41) into a mudtank (43) typically located just below the fine shaker (41). From themud tank, the fluid will enter a centrifuge (46) which will separate outanother damp solids component (65) and send a fluid component to a 3phase centrifuge (51). From the 3 phase centrifuge will come anadditional damp solids component (67), clean mud (23) and water (25).

Turning now to the truck solids (30B), they may be stored “unmixed” (16)or in a storage pile of dried truck solids (17) (see FIG. 1). Eitherway, truck solids (30B) may be deposited, typically using a backhoe (orfront loader) and a hopper and a conveyor belt onto a coarse shaker (45)off the top of which come particles which will be a course component(69). Much of the truck solids (30B) will, however, fall through thecoarse shaker (45) and these are transported or dropped into acentrifugal drier (47). The centrifugal drier (47) will yield a treatedoil and gas waste/road base component material (29C) and a liquidportion (49) which will be transported to mud tank (43) (see FIG. 3A forprocessing).

Thus it is seen that both tank liquids (30A) and truck solids (30B)coming from oil and gas waste material sites (32) will undergo somephysical separation of some solids from liquids, the liquid portion ofwhich will typically end up in mud tank (43). The liquids in mud tank(43) will undergo a process that yields a treated oil and gas wastematerial/road base component material (29) and also clean mud (23) andwater (25).

Novelty is achieved in taking oil and gas waste material including tankliquids and truck solids and making a road base that meets industrystandards and is environmentally safe. From the solids a liquid isextracted by stacking, dry mixing or mechanical separation. From thetank liquids a solid portion and a clean mud portion and water isproduced (see FIGS. 3 and 3A). Depending on weather, type of or sourceof waste material, extent of drying desired, economic consideration,environmental consideration may dictate which of the three types, orcombination of the three types will be used.

The oil and gas waste material that is treated according to Applicant'spresent invention usually contains a solid phase and a liquid phase. Itis Applicant's novel methods of treatment that help remove a part of theliquid phase. The following areas list of some of the oil and gas wastematerial that may be subject to Applicant's novel treatment and use andApplicant's novel roadbase:

-   -   Basic sediment and water (BS&W) and tank bottoms;    -   Condensate;    -   Deposits removed from piping and equipment prior to        transportation (i.e., pipe scale hydrocarbon solids, hydrates        and other deposits);    -   Drilling fluids and cuttings from offshore operations disposed        of onshore;    -   Hydrogen sulfide scrubber liquid and sludge;    -   Liquid and solid wastes generated by crude oil and tank bottom        reclaimers;    -   Weathered oil;    -   Pigging wastes from producer operated gathering lines;    -   Pit sledges and contaminated bottoms from storage or disposal of        exempt wastes;    -   Produced sand;    -   Produced water constituents removed before disposal (injection        or other disposal);    -   Slop oil (waste crude oil from primary field operations and        production);    -   Crude oil contaminated soil;    -   Tank bottoms and basic sediments and water (BS&W) from: storage        facilities that hold product, exempt and non-exempt waste        (included accumulated material such as hydrocarbons, solids,        sands and emulsion from production separators, fluid treating        vessels, production and refining impoundments);    -   Work over wastes (i.e., blowdown, swabbing and balling wastes);    -   Unused methanol;    -   Used equipment lubricating oil;    -   Paint and paint wastes;    -   Pipe dope (unused),    -   Refinery wastes (e.g. tank bottoms);    -   Compressor oil and blowdown wastes;    -   Unused drilling fluids;    -   Chemical contaminated soil;    -   Lube oil contaminated soil;    -   Spent solvents, including wastes solvents;    -   Hydraulic fluids (contaminated);    -   Waste in transportation pipeline related pits,    -   Cement slurry returns from the well and cement cuttings;    -   Produced water—contaminated soils; and    -   PCB (polychlorinated biphynols) contaminated soils.

The attached FIGS. 4 and 5 illustrate at least part of an alternatepreferred method for treatment of oil and gas, and more specifically forthe treatment of drilling waste. Drilling waste is intended to identifywaste more specifically than oil and gas waste. That is, drilling wasteis waste material directly associated with the drilling of a well.Drilling waste is typically in the nature of: drill cuttings, drillingmud, and clean up material from a drilling location. Applicant has foundthat the method set forth herein and hereinabove may be advantageouslyand more specifically directed to drilling waste, accumulated fromoffsite and shipped to Applicant's site for processing and combined withaggregate, the aggregate also typically trucked in from offsite. In thismanner, drilling waste may be effectively combined with an aggregate toform an environmentally safe road base capable of passing mostgovernmental agency standards and engineered to pass tests to determineits structural soundness.

The roadbase compositions prepared by the methods set forth in FIGS. 4and 5 may be mixed in accordance with the recipes set forth hereinabove,with asphalt emulsion as an optional additive. Further, while themethods, devices and compositions set forth in these specifications aresatisfactory with most oil and gas waste as set forth herein, drillingwastes are favorably disposed of and converted herein to anenvironmentally compatible and soundly engineered road base.

In FIGS. 4 and 5, methods and devices are provided that will assist inefficiently handling oil and gas waste, but more specifically drillingwaste. It will be noticed with reference to the figures that Applicantmay utilize a conveyor system which may be screw or auger conveyors (orbelt conveyors, pneumatic pressure feed, or direct feed with heavyequipment) for the transport of materials, from any one location to anyother location, in applying the method of Applicant's present invention.

Turning now to FIG. 4, Applicant discloses a pile of, typically, stackedaggregate (61), brought to Applicant's site from, typically, an offsitelocation. Applicant also discloses a pile, typically stacked, ofdrilling waste (101). This drilling waste originated offsite, beingtransported to Applicant's facility typically by trucks and/or bargesand the like. The material (61/101) is typically underlain by animpervious layer and may or may not include a berm. Excavators (105), orbackhoes or the like with front-end loaders attached thereto may scoopand transport material (61/101) to a screen shaker (108) for separationof large chunks of material, typically greater than about 3 to 4 inchesin their narrowest dimension from the mix that will then directly enterpugmill or other mixer (112). Optionally, excavators (105) may loadaggregate (61) and/or drilling waste (103) onto a screen and/or shaker(108) with the droppings going into a screw auger (104, 106), whichtypically contains a hopper (104A, 105A) thereon for transportation tothe mixer.

In the alternative, pugmill (112) may be placed directly beneath shaker(108) with the shaker loaded by heavy equipment or a conveyor. Screwconveyor (114) having a hopper (114A) thereon may be placed beneath oradjacent pugmill (112) for transporting the mixed material, now roadbase material, to a stacking location typically underlain by animpervious layer, here seen as road base material (20). In thealternative, the pugmill can dump its contents directly on the ground.

Thus, it is seen that Applicant has provided for the transportation ofmaterials through the use of a conveyor system and has, further,provided for the introduction of drilling waste on the one hand andaggregate (61) on the other, either contemporaneously or sequentiallyinto a screen shaker for initial separation followed by conveyance to apugmill. It is noted that, optionally, liquids may be removed fromdrilling waste material (101) before movement to the shaker screen andpugmill according to FIG. 4. It is to be understood that the same screwconveyor (or belt conveyor, pneumatic conveyor, or direct feed) may beused to first take one of the aggregate or drilling waste to the pugmillthen the other. Wherever either of these materials need to be conveyedfrom its storage point to the pugmill and/or shaker, any one of: a screwconveyor, a belt conveyor, a pneumatic pipe/air pressurized deliverysystem, or direct feed (heavy equipment) may be used.

FIG. 5 illustrates the use of yet another screw conveyor (116). Here,Applicant has found it effective to combine liquids received as drillingwaste, typically held in a container or tank (103), with drilling wastematerial that is received in trucks and is typically drier, heredrilling waste material (101) (typically stored on an impermeable pad).An excavator (105) may be used to load a hopper of screw conveyer (116),creating a stackable mass (111) of waste material, comprising liquidcomponents of drilling waste and solid stackable components of drillingwaste material (101) thereof. An excavator or loader and a screwconveyor may be used to form a stackable mass (111) of drilling waste.This drilling waste may be further processed according to methods andwith equipment set forth herein to produce an environmentally compatibleeffective road base material according to the method set forth herein.

It is noted that the use of the screw conveyors, conveyor belts,pneumatic delivery systems and/or direct feed by heavy equipment, mayallow effective transportation of material from one point to another atApplicant's facility regardless of the liquid hydrocarbon componentthereof and even in inclement weather. The use of a screw auger allowssome mixing during the transportation process, therefore furthereffectuating, such as set forth in FIG. 5, the creation of a stackablewaste material that still has a liquid component typically not, however,to the point of saturation.

With respect to FIG. 5, it is seen that liquids from drilling wastematerials are brought from offsite locations by vacuum trucks and/orbarges. Typically, however, waste material (101) as identified in FIG. 5from drilling sites is typically brought in via dump truck and simplydumped on the impervious pad.

Further, Applicant has found through testing that a particular type ofcentrifuge works best for the drilling mud production process set forthherein (see FIG. 2). These specifications of the centrifuge are asfollows: Three phase, with an external adjustable skimmer. One suchthree phase centrifuge is available from Flotwig.

Applicant provides a conveyor system for movement of drilling wasteand/or aggregate about Applicant's treatment site. The conveyor systemmay be one or more: belt conveyors; screw conveyors; pneumatic pressurefeed conveyors, or direct feed (that is by heavy equipment such asfront-end loaders). Optionally, a screen or shaker may be used at anypoint in the conveying system where it desired to remove larger chunksfrom entry into either belt conveyor or screw conveyor or the pugmill.Further, while aggregate is typically transported from offsite, thetreatment facility may be built on a site where aggregate is readilyavailable, such as a caliche pit.

Although the invention has been described with reference to specificembodiments, this description is not meant to be construed in a limitedsense. Various modifications of the disclosed embodiments, as well asalternative embodiments of the inventions will become apparent topersons skilled in the art upon the reference to the description of theinvention. It is, therefore, contemplated that the appended claims willcover such modifications that fall within the scope of the invention.

1. A method of creating a road base material comprising the steps of:obtaining an oil and gas waste material; obtaining an aggregatematerial; removing a liquid component of the oil and gas waste material;screening the oil and gas waste material; screening the aggregate; andmixing the aggregate and oil and gas waste, the mixing step includingadding water and cement.
 2. The method of claim 1, wherein the oil andgas waste material includes waste material from a production site. 3.The method of claim 2, further including the step of crushing theaggregate before screening the aggregate.
 4. The method of claim 2,further including the step of storing, after obtaining, the oil and gaswaste material on an impervious layer.
 5. The method of claim 2, whenthe moving step includes removing oil and clean mud.
 6. The method ofclaim 2, wherein, after removing the liquid component containing someoil and some water, the oil and water is separated into an oil componentand water component.
 7. The method of claim 2, wherein the removing stepis accomplished by physical separation of some of the liquid base fromthe production waste material.
 8. The method of claim 7, wherein themixing step is accomplished via batch mixing.
 9. The method of claim 2,wherein the screening of the production waste material includes shaking.10. The method of claim 1, wherein the oil and gas waste materialincludes material in the nature of drilling waste material.
 11. Themethod of claim 10, further including the step of crushing the aggregatebefore screening the aggregate.
 12. The method of claim 10, furtherincluding the step of storing, after obtaining, the oil and gas wastematerial on an impervious layer.
 13. The method of claim 10, when themoving step includes removing oil and clean mud.
 14. The method of claim10, wherein, after removing the liquid component containing some oil andsome water, the oil and water is separated into an oil component andwater component.
 15. The method of claim 10, wherein the removing stepis accomplished by physical separation of some of the liquid base fromthe production waste material.
 16. The method of claim 15, wherein themixing step is accomplished via batch mixing.
 17. The method of claim10, wherein the screening of the production waste material includesshaking.